posted on 2019-10-22, 13:55authored byJ Zinke, A Rountrey, M Feng, S-P Xie, D Dissard, K Rankenburg, JM Lough, MT McCulloch
Variability of the Leeuwin current (LC) off Western Australia is a footprint of interannual and decadal climate variations in the tropical Indo-Pacific. La Niña events often result in a strengthened LC, high coastal sea levels and unusually warm sea surface temperatures (SSTs), termed Ningaloo Niño. The rarity of such extreme events and the response of the southeastern Indian Ocean to regional and remote climate forcing are poorly understood owing to the lack of long-term records. Here we use well-replicated coral SST records from within the path of the LC, together with a reconstruction of the El Niño-Southern Oscillation to hindcast historical SST and LC strength from 1795 to 2010. We show that interannual and decadal variations in SST and LC strength characterized the past 215 years and that the most extreme sea level and SST anomalies occurred post 1980. These recent events were unprecedented in severity and are likely aided by accelerated global ocean warming and sea-level rise.
Funding
We acknowledge the Australian Institute of Marine Science coral core sampling campaign conducted using the RV Solander under the leadership of Dr Tim Cooper and with assistance from D.D. (UWA). J.Z. was supported by an Indian Ocean Marine Research Centre UWA/AIMS/CSIRO collaborative assistant professorial fellowship. A.R. is supported by a grant from the Australian National Network in Marine Science with the Centre for Marine Futures at UWA Oceans Institute. M.F. is supported by the CSIRO Wealth from Oceans Flagship. M.F. is also supported by the Australian Climate Change Science Programme (ACCSP). M.T.M., M.J.L. and D.D. activities are conducted under the auspices of the ARC Centre of Excellence for Coral Reef Studies with D.D. being supported by ARC DP0986505. M.J.L. was supported by AIMS. M.T.M. was a recipient of a Western Australian Premiers Fellowship kindly provided by the WA Premiers Department. Laboratory facilities were constructed using funds provided by an ARC LIEF grant 100100203, UWA and partner institutions. We thank the West Australian Biogeochemistry Centre, in particular G. Skrzypek and P. Grierson, for stable isotope measurements. Kirsty Brooks from UWA helped milling the samples. Eric Matson from AIMS provided skilled technical support for coral core collection and sample preparation.
History
Citation
Nature Communications, 2014, 5:3607
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/School of Geography, Geology and the Environment